A test kit to perform PTT determinations is already available in the market providing the necessary reagent in the form of a lyophilized agent which must be reconstituted.
One disadvantage of the commercial test kit for PTT determination is that the sensitivity to heparin still leaves a great deal to be desired so that it is not of much use for the control of heparin therapy.
The object of the present invention is to raise the known PTT test kit's sensitivity, in particular its sensitivity to low-molecular heparin fractions, to a degree also allowing the control of heparin therapy.